Anisotropic conductive material body, display apparatus, method for producing the display apparatus, and conductive member

ABSTRACT

An anisotropic conductive material body includes an insulating medium; and a plurality of conductive members dispersed in the medium. At least a surface of each of the plurality of conductive members is conductive. A force is applied to at least one of the plurality of conductive members so as to change the at least one conductive member, so that the conductive property of the anisotropic conductive material body provided by the at least one conductive member is changed to an insulating property.

This non-provisional application claims priority under 35 U.S.C.,§119(a), on Patent Applications Nos. 2003-161316 filed in Japan on Jun.5, 2003 and 2004-160269 filed in Japan on May 28, 2004, the entirecontents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an anisotropic conductive materialbody, a display apparatus, a method for producing the display apparatus,and a conductive member. More specifically, the present inventionrelates to an anisotropic conductive material body usable forelectrically connecting electronic components, a display apparatusincluding a driving circuit mounted using such an anisotropic conductivematerial body, a method for producing the display apparatus, and aconductive member suitable for the anisotropic conductive material body.

2. Description of the Related Art

In a display apparatus such as, for example, a liquid crystal displayapparatus, a driving signal which is output from a driving circuit isinput to a display panel. In a general display apparatus, a displaypanel including a plurality of pixels is provided with a plurality ofpanel connectors at a fine pitch. The driving circuit includes aplurality of driving circuit connectors. The plurality of drivingcircuit connectors respectively correspond to, and connect with, thepanel connectors.

The driving circuit is mounted on the display panel by TAB (TapeAutomated Bonding), COG (Chip On Glass) or the like. For such a mannerof mounting, an anisotropic conductive layer is used.

Japanese Laid-Open Publication No. 6-59268 discloses a structure formounting a driving circuit on a display panel using an anisotropicconductive layer.

FIG. 4 is a schematic cross-sectional view of a mounting structuredisclosed in Japanese Laid-Open Publication No. 6-59268.

The mounting structure shown in FIG. 4 is provided on a peripheralportion of a liquid crystal display panel 30 as more specificallydescribed below. On the peripheral portion, a plurality of panelconnectors 31 are provided at a fine pitch. The plurality of panelconnectors 31 receive, for example, a driving signal for driving theliquid crystal display panel 30. Also on the peripheral portion, adriving circuit 33 for supplying a driving signal or the like is mountedby an anisotropic conductive layer 34. The driving circuit 33 is asource COF (Chip on Film) section, a gate COF section, or the like.

The plurality of panel connectors 31 are provided so as to project froma surface of the liquid crystal display panel 30 toward the drivingcircuit 33. A plurality of driving circuit connectors 33 a are providedso as to project from a surface of the driving circuit 33 toward theliquid crystal display panel 30. The plurality of driving circuitconnectors 33 a are located to face the corresponding panel connectors31, respectively.

An anisotropic conductive layer 34 includes a synthetic resin 34 a, aplurality of conductive particles 34 b dispersed in the synthetic resin34 a, and a plurality of insulating particles 34 c dispersed in thesynthetic resin 34 a. The plurality of conductive particles 34 b containmetal such as nickel or the like. The synthetic resin 34 a has anadhering property and acts as an adhesive.

The driving circuit 33 is bonded to the peripheral portion of the liquidcrystal display panel 30 with the synthetic resin 34 a. The plurality ofdriving circuit connectors 33 a and the corresponding panel connectors31 are electrically connected to each other with the conductiveparticles 34 b, respectively. Accordingly, a driving signal which isoutput from the driving circuit 33 is input to the liquid crystaldisplay panel 30 via the driving circuit connectors 33 a, the conductiveparticles 34 b, and the panel connectors 31.

The mounting structure shown in FIG. 4 is produced as follows.

The anisotropic conductive layer 34 is provided so as to cover the panelconnectors 31 which are located on the peripheral portion of the liquidcrystal display panel 30. The driving circuit 33 with the drivingcircuit connectors 33 a is located on the anisotropic conductive layer34. The driving circuit 33 is positioned with respect to the liquidcrystal display panel 30 such that the driving circuit connectors 33 aface the corresponding the panel connectors 31, respectively.

In this state, the driving circuit 33 is pressed on the anisotropicconductive layer 34, and the anisotropic conductive layer 34 is heated.When the anisotropic conductive layer 34 is heated, the synthetic resin34 a becomes a dissolved state, and the conductive particles 34 bdispersed in the synthetic resin 34 a flow into areas between thedriving circuit connectors 33 a and the corresponding panel connectors31. The driving circuit connectors 33 a and the corresponding panelconnectors 31 are electrically connected to each other with theconductive particles 34 b. Then, the synthetic resin 34 a is cured, andthus the driving circuit 33 is mounted on the peripheral portion of theliquid crystal display panel 30.

Japanese Laid-Open Publication No. 5-29386 discloses a mountingstructure using an anisotropic conductive layer.

FIG. 5 is a schematic cross-sectional view disclosed in JapaneseLaid-Open Publication No. 5-29386.

In the mounting structure shown in FIG. 5, a plurality of panelconnectors 41 are provided at a fine pitch on a peripheral portion of aliquid crystal display panel 40.

The plurality of panel connectors 41 are provided so as to project froma surface of the liquid crystal display panel 40 toward a drivingcircuit 43. A plurality of driving circuit connectors 43 a are providedso as to project from a surface of the driving circuit 43 toward theliquid crystal display panel 40.

An anisotropic conductive layer 45 includes a synthetic resin 45 a and aplurality of conductive particles 45 b dispersed in the synthetic resin45 a. The synthetic resin 45 a acts as an adhesive.

In the mounting structure shown in FIG. 5, the plurality of panelconnectors 41 each have a recessed portion 41 a.

The depth of the recessed portion 41 a is smaller than the particlediameter of the conductive particles 45 b dispersed in the syntheticresin 45 a.

Owing to such a depth of the recessed portion 41 a, the conductiveparticles 45 b flowing in the recessed portion 41 a are suppressed fromflowing out from the recessed portion 41 a. Therefore, a bottom surfaceof the recessed portion 41 a and the corresponding driving circuitconnector 43 a are electrically connected to each other with certaintyby the conductive particles 45 b.

In the mounting structure shown in FIG. 4, the panel connectors 31project from the surface of the liquid crystal display panel 30 and thedriving circuit connectors 33 a project from a surface of the drivingcircuit 33. Therefore, the gap between the panel connectors 31 and thedriving circuit connectors 33 a is small. By contrast, the gap betweenan upper surface of a portion of the liquid crystal display panel 30which does not have a panel connector 31 thereon, and a lower surface ofa portion of the driving circuit 33 which does not have a drivingcircuit connector 33 a thereon, is larger. Therefore, the anisotropicconductive layer 34 needs to be thick in order to mount the drivingcircuit 33 on the liquid crystal display panel 30. Production of such athick anisotropic conductive layer 34 requires a larger amount ofsynthetic resin 34 a, which increases the production cost.

In the mounting structure shown in FIG. 5, the panel connectors 41project from the surface of the liquid crystal display panel 40 and thedriving circuit connectors 43 a project from the surface of the drivingcircuit 43. Therefore, the gap between the panel connectors 41 and thedriving circuit connectors 43 a is small. By contrast, the gap betweenan upper surface of a portion of the liquid crystal display panel 40which does not have a panel connector 41 thereon, and a lower surface ofa portion of the driving circuit 43 which does not have a drivingcircuit connector 43 a thereon, is larger. Therefore, the anisotropicconductive layer 45 needs to be thick in order to mount the drivingcircuit 43 on the liquid crystal display panel 40. Production of such athick anisotropic conductive layer 45 requires a larger amount ofsynthetic resin 45 a, which increases the production cost.

In order to solve these problems, another mounting structure isproposed.

FIG. 6 is a cross-sectional view illustrating another conventionalmounting structure.

In the mounting structure shown in FIG. 6, one continuous panelconnector 51 is provided for one driving circuit 53, without beingdivided to correspond to a plurality of driving circuit connectors 53 a.The panel connector 51 has a plurality of recessed portions 51 arespectively facing the plurality of driving circuit connectors 53 a.The depth of each recessed portion 51 a is smaller than the particlediameter of conductive particles 55 b of an anisotropic conductive layer55.

On a bottom surface of each recessed portion 51 a, a connector 51 b isprovided. The plurality of connectors 51 b are provided at a fine pitch.

The conductive particles 55 b are each in contact with, and thuselectrically connect, the corresponding driving circuit connector 53 aand the corresponding connector 51 b.

A driving signal which is output from the driving circuit 53 is input toa liquid crystal display panel 50 via the driving circuit connectors 53a, the conductive particles 55 b, the connectors 51 b, and the panelconnectors 51.

In this mounting structure, the driving circuit connector 53 a iselectrically connected to the connector 51 b with certainty by theconductive particles 55 b flowing in the recessed portion 51 a of thepanel connector 51. The gap between the upper surface of a portion ofthe panel connector 51 which does not have a recessed portion 51 athereon, and the lower surface of a portion of the driving circuit 53which does not have a driving circuit connector 53 a thereon, is small.This allows the anisotropic conductive layer 55 used for mounting thedriving circuit 53 to be thinner.

However, in the mounting structure shown in FIG. 6, each conductiveparticle 55 b needs to have a large particle diameter such that theconductive particle 55 b can contact both the driving circuit connector53 a and the connector 51 b located on the bottom surface of therecessed portion 51 a. For example, the conductive particle 55 b needsto have a particle diameter of 10 μm or greater.

When the particle diameter of the conductive particle 55 b is thatlarge, the conductive particle 55 b is compressed to be flatter in a gapbetween the upper surface of the panel connector 51 and the lowersurface of a portion of the driving circuit 53 which does not have thedriving circuit connector 53 a. This may cause an undesirable resultthat adjacent conductive particles 55 b contact, and to be conductiveto, each other.

The driving circuit connectors 53 a are provided at a fine pitch, likethe recessed portions 51 a of the panel connector 51. The pitch isusually about 100 μm. When the driving circuit connectors 53 a areprovided at such a fine pitch, the particle diameter of the conductiveparticles 55 b of about 10 μm may cause the following undesirableresult. When the conductive particles 55 b are compressed to be flatter,adjacent conductive particles 55 b become conductive to each otherbetween two adjacent driving circuit connectors 53 a and thus theadjacent driving circuit connectors 53 a are short circuited.

The possibility that the above undesirable result occurs is low if theparticle diameter of the conductive particles is about 3 to 5 μm.However, it cannot be guaranteed that such small conductive particleselectrically connect the driving circuit connectors 53 a and theconnectors 51 b on the bottom surfaces of the recessed portions 51 a ofthe panel connector 51 to each other.

SUMMARY OF THE INVENTION

According to one aspect of the invention, an anisotropic conductivematerial body includes an insulating medium; and a plurality ofconductive members dispersed in the medium. At least a surface of eachof the plurality of conductive members is conductive. A force is appliedto at least one of the plurality of conductive members so as to changethe at least one conductive member, so that the conductive property ofthe anisotropic conductive material body provided by the at least oneconductive member is changed to an insulating property.

In one embodiment of the invention, the medium is adhesive.

In one embodiment of the invention, the medium is formed of a syntheticresin.

In one embodiment of the invention, the plurality of conductive membersare a plurality of conductive particles.

In one embodiment of the invention, the plurality of conductive memberseach include a plurality of insulating particles and a conductiveplating cover for covering the plurality of insulating particles. Thechange in the at least one conductive member includes breakage of theconductive plating cover of the at least one conductive member.

In one embodiment of the invention, the plurality of conductive membersare a plurality of conductive particles. The plurality of conductiveparticles each have a particle diameter of 10 to 20 μm inclusive, andthe plurality of insulating particles each have a particle diameter of 2to 5 μm inclusive.

In one embodiment of the invention, the change in the at least oneconductive member includes division of the at least one conductivemember.

In one embodiment of the invention, the anisotropic conductive materialbody further includes a plurality of insulating particles dispersed inthe medium.

In one embodiment of the invention, the plurality of insulatingparticles each have a particle diameter of 2 to 20 μm inclusive.

In one embodiment of the invention, the medium is film-like.

According to another aspect of the invention, a display apparatusincludes a display panel; a driving circuit for driving the displaypanel; a driving circuit connector provided on the driving circuit; apanel connector provided on the display panel; and an anisotropicconductive material body for electrically connecting the driving circuitconnector and the panel connector to each other. The anisotropicconductive material body includes an insulating medium, and a pluralityof conductive members dispersed in the medium. At least a surface ofeach of the plurality of conductive members is conductive. A force isapplied to at least one of the plurality of conductive members so as tochange the at least one conductive member, so that the conductiveproperty of the anisotropic conductive material body provided by the atleast one conductive member is changed to an insulating property.

In one embodiment of the invention, the anisotropic conductive materialbody is used for mounting the driving circuit on the display panel.

In one embodiment of the invention, a gap between the driving circuitconnector and the panel connector is larger than a gap between a portionof the driving circuit, which is not in correspondence with the drivingcircuit connector, and the panel connector.

In one embodiment of the invention, the anisotropic conductive materialbody is provided between the driving circuit and the display panel andbetween the driving circuit connector and the panel connector. A gapbetween the driving circuit connector and the panel connector isdesigned such that the conductive property provided by the conductivemember existing in the gap is not changed to an insulating property; anda gap between the portion of the driving circuit, which is not incorrespondence with the driving circuit connector, and the panelconnector is designed such that the conductive property provided by theconductive member existing in the gap is changed to an insulatingproperty.

In one embodiment of the invention, the panel connector has a recessedportion facing the driving circuit connector.

In one embodiment of the invention, the plurality of conductive memberseach includes a plurality of insulating particles and a conductiveplating cover for covering the plurality of insulating particles. Thechange in the at least one conductive member includes breakage of theconductive plating cover of the at least one conductive member.

In one embodiment of the invention, the change in the at least oneconductive member includes division of the at least one conductivemember.

According to still another aspect of the invention, a method forproducing a display apparatus including a display panel; a drivingcircuit for driving the display panel; a driving circuit connectorprovided on the driving circuit; a panel connector provided on thedisplay panel; and an anisotropic conductive material body forelectrically connecting the driving circuit connector and the panelconnector to each other is provided. The method includes the steps ofmounting the driving circuit on the display panel with an anisotropicconductive material body, the anisotropic conductive material bodyincluding an insulating medium and a plurality of conductive membersdispersed in the medium, at least a surface of each of the plurality ofconductive members being conductive; and insulating a prescribed portionof the anisotropic conductive material body, in which a force is appliedto at least one of the plurality of conductive members so as to changethe at least one conductive member, so that the conductive property ofthe anisotropic conductive material body provided by the at least oneconductive member is changed to an insulating property.

In one embodiment of the invention, the plurality of conductive memberseach include a plurality of insulating particles and a conductiveplating cover for covering the plurality of insulating particles. In thestep of insulating the prescribed portion of the anisotropic conductivematerial body, the change in the at least one conductive member includesbreakage of the conductive plating cover of the at least one conductivemember.

In one embodiment of the invention, in the step of insulating theprescribed portion of the anisotropic conductive material body, thechange in the at least one conductive member includes division of the atleast one conductive member.

In one embodiment of the invention, the step of mounting the drivingcircuit on the display panel includes the step of locating theanisotropic conductive material body between the driving circuit and thedisplay panel and between the driving circuit connector and the panelconnector. The step of insulating the prescribed portion of theanisotropic conductive material body includes the step of compressingthe conductive member located between the panel connector and theportion of the driving circuit, which is not in correspondence with thedriving circuit connector, without compressing the conductive memberlocated between the driving circuit connector and the panel connector.

In one embodiment of the invention, the panel connector has a recessedportion facing the driving circuit connector.

In one embodiment of the invention, the step of insulating theprescribed portion of the anisotropic conductive material body includesthe step of pressurizing the driving circuit with a prescribed pressure.

According to still another aspect of the invention, a conductive memberis provided. At least a surf ace of the conductive member is conductive,and the conductive member is changed by a force applied thereto.

In one embodiment of the invention, the conductive member comprises aplurality of insulating particles and a conductive plating cover forcovering the plurality of insulating particles. The conductive platingcover is broken when a force is applied to the conductive member.

In one embodiment of the invention, the conductive member is aconductive particle, wherein the conductive particle has a diameter of10 to 20 μm inclusive, and the plurality of insulating particles eachhave a particle diameter of 2 to 5 μm.

In one embodiment of the invention, the conductive member is divided bya force applied thereto.

According to the present invention, the conductive property of aprescribed portion of an anisotropic conductive material body providedby the conductive member can be changed to an insulating property, byapplying a force to the conductive member such that the conductivemember dispersed in the medium is changed. In this manner, theconductive property of a prescribed portion of the anisotropicconductive material body is changed to an insulating property. When theconductive member is supplied with no force or is not supplied with asufficient force to change the conductive member, the prescribed portionof the anisotropic conductive material body can be kept conductive.

In a display apparatus according to the present invention which usessuch an anisotropic conductive material body, the panel connector andthe driving circuit connector can be electrically connected with eachother. Adjacent driving circuit connectors arranged at a fine pitch canbe insulated from each other. Thus, the reliability of the mountingstructure for mounting the driving circuit on the display panel can besignificantly improved.

A method for producing a display apparatus according to the presentinvention allows a highly reliable mounting structure to be producedeasily.

The present invention provides a conductive member suitable to theanisotropic conductive material body.

Thus, the invention described herein makes possible the advantages ofproviding an anisotropic conductive material body which can electricallyconnect the driving circuit connectors and the connectors on the displaypanel, provided at a fine pitch with certainty, a display apparatususing such an anisotropic conductive material body, a method forproducing such a display apparatus, and a conductive member suitable forthe anisotropic conductive material body.

These and other advantages of the present invention will become apparentto those skilled in the art upon reading and understanding the followingdetailed description with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a liquid crystal display apparatus according toan example of the present invention;

FIG. 2 is a cross-sectional view of a mounting structure of a source COFsection of the liquid crystal display apparatus shown in FIG. 1;

FIG. 3 is a cross-sectional view of a mounting structure of a source COFsection of a liquid crystal display apparatus according to anotherexample of the present invention;

FIG. 4 is a cross-sectional view of a conventional mounting structure;

FIG. 5 is a cross-sectional view of another conventional mountingstructure; and

FIG. 6 is a cross-sectional view of still another conventional mountingstructure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described by way ofillustrative examples with reference to the accompanying drawings.

In the following description, a liquid crystal display apparatus will beused as one form of a display apparatus according to the presentinvention. The present invention is not limited to a liquid crystaldisplay apparatus, A display apparatus according to the presentinvention may be a PDP (Plasma Display Panel) display apparatus, an EL(Electroluminescence) display apparatus, or the like.

FIG. 1 is a schematic plan view of a liquid crystal display apparatus 1according to one example of the present invention.

The liquid crystal display apparatus 1 includes a liquid crystal displaypanel 10 acting as a display panel; a plurality of source COF (Chip onFilm) sections 21 each acting as a driving circuit for driving theliquid crystal display panel 10; a plurality of gate COF sections 22each acting as a driving circuit for driving the liquid crystal displaypanel 10; a signal input FPC (Flexible Printed Circuit) section 23 forsupplying a driving signal or the like for the liquid crystal displaypanel 10 to the source COF sections 21 and the gate COF sections 22, asource anisotropic conductive layer 25 for mounting the source COFsections 21 on the liquid crystal display panel 10; and a gateanisotropic conductive layer 26 for mounting the gate COF sections 22 onthe liquid crystal display panel 10. The source COF sections 21, and thegate COF sections 22 have substantially the same structure.

The liquid crystal display panel 10 is provided with a panel connector(not shown in FIG. 1). The panel connector includes a plurality ofsource connectors 15 (FIG. 2), a plurality of gate connectors (notshown), and a common panel connector (not shown).

One driving circuit is provided with a plurality of driving circuitconnectors (not shown in FIG. 1).

In more detail, one source COF section 21 includes a plurality of sourceCOP section connectors 21 a (FIG. 2), and one gate COF section 22includes a plurality of gate COF section connectors (not shown).

The liquid crystal display panel 10 includes a TFT (Thin FilmTransistor) substrate 11, a color filter substrate 12, and a liquidcrystal layer (not shown) filling the space between the TFT substrate 11and the color filter substrate 12. The TFT substrate 11 and the colorfilter substrate 12 are located to face each other with a prescribeddistance therebetween. The TFT substrate 11 includes a glass plate 11 a(FIG. 2) having a thickness of 0.4 mm to 0.7 mm, gate lines, sourcelines, and TFTs acting as switching devices. The gate lines, the sourcelines, and the TFTs are provided on the glass plate. The color filtersubstrate 12 includes another glass plate and a color filter providedthereon.

The TFT substrate 11 is rectangular, and the planar shape of the colorfilter substrate 12 is slightly smaller than that of the TFT substrate11. The color filter substrate 12 is located such that an edge portionalong a longer side of the TFT substrate 11 and an edge portion along ashorter side of the TFT substrate 11 are exposed. Hereinafter, theexposed edge portion along the longer side will be referred to as a“source-side edge portion”, and the exposed edge portion along theshorter side will be referred to as a “gate-side edge portion”.

On the source-side edge portion of the TFT substrate 11, a plurality ofsource connectors for receiving a source signal or the like to be sentto the TFT substrate 11 are provided along the longer side of the TFTsubstrate 11. The plurality of source connectors respectively correspondto the plurality of source COP sections 21. The plurality of sourceconnectors are connected to the plurality of source lines included inthe TFT substrate 11.

On the gate-side edge portion of the TFT substrate 11, a plurality ofgate connectors for receiving a gate signal or the like to be sent tothe TFT substrate 11 are provided along the shorter side of the TFTsubstrate 11. The plurality of gate connectors respectively correspondto the plurality of gate COF sections 22. The plurality of gateconnectors are connected to the plurality of gate lines included in theTFT substrate 11.

On a portion of the source-side edge portion which is proximate to thegate-side edge portion, a common panel connector (not shown) forsupplying a prescribed signal to the TPT substrate 11 is provided.

On the source-side edge portion of the TFT substrate 11, a sourceanisotropic conductive layer 25 is provided along the longer side of theTFT substrate 11. The source COF sections 21 are located on the sourceanisotropic conductive layer 25 at a prescribed interval along thelonger side of the TFT substrate 11. The source COF sections 21 are eachelectrically connected to the corresponding source connector 15 (FIG. 2)via the source anisotropic conductive layer 25. The source COF sections21 are mounted on the TFT substrate 11 by the source anisotropicconductive layer 25.

On the gate-side edge portion of the TFT substrate 11, a gateanisotropic conductive layer 26 is provided along the shorter sides ofthe TFT substrate 11. The gate COF sections 22 are located on the gateanisotropic conductive layer 26 at a prescribed interval along theshorter side of the TFT substrate 11. The gate COF sections 22 are eachelectrically connected to the corresponding gate connector (not shown)via the gate anisotropic conductive layer 26. The gate COF sections 22are mounted on the TFT substrate 11 by the gate anisotropic conductivelayer 26.

On a portion of the source-side edge portion which is proximate to thegate-side edge portion, the signal input FPC section 23 is provided. Oneend of the signal input FPC section 23 is connected to an end of thesource anisotropic conductive layer 25 provided on the source-side edgeportion. The one end of the signal input FPC section 23 and the commonpanel connector provided on the TFT substrate 11 are electricallyconnected to each other via the source anisotropic conductive layer 25.The signal input FPC section 23 is mounted on the TFT substrate 11 viathe source anisotropic conductive layer 25. The other end of the signalinput FPC section 23 is connected to a driving circuit substrate (notshown).

The source COF sections 21 and the gate COF sections 22 each include athin film substrate formed of a polyimide resin or the like and having athickness of 25 μm to 40 μm, and a wiring pattern formed of a copperfoil or the like and having a thickness of 8 μm to 12 μm. The wiringpattern is formed on the thin film substrate by a plating method or acasting method. In the vicinity of the center of the thin filmsubstrate, a driving IC is provided. The wiring pattern of each of thesource COF sections 21 and the gate COP sections 22 has a solder resiststacked thereon, except on an area which is connected to the sourceanisotropic conductive layer 25 or the gate anisotropic conductive layer26. The solder resist is formed of an insulating material such aspolyimide or the like, and has a thickness of 25 μm to 50 μm.

The source COF sections 21 and the gate COF sections 22 may have variouscomponents for driving the liquid crystal display panel 10 other thanICs.

FIG. 2 is a cross-sectional view of FIG. 1 taken along line A–A′ inFIG. 1. More specifically, FIG. 2 shows amounting structure of thesource-side edge portion. A mounting structure of the gate-side edgeportion has substantially the same structure.

On the glass plate 11 a included in the TFT substrate 11, a sourceconnector 15 (included in the panel connector) is provided. Onecontinuous source connector 15 is provided for one source COF section21. The source connector 15 includes a plurality of recessed portions 15a, which correspondingly face a plurality of source COF sectionconnectors 21 a respectively. The plurality of source COF sectionconnectors 21 a are provided on the source COP section 21. The pluralityof source COF section connectors 21 a are arranged at a fine pitch ofabout 100 μm, and thus the plurality of recessed portions 15 a arearranged at a fine pitch of about 100 μm. The depth of each recessedportion 15 a is smaller than the particle diameter of conductiveparticles 25 b of the source anisotropic conductive layer 25.

On a bottom surface of each recessed portion 15 a, a connector 15 b isprovided. The plurality of connectors is 15 b are arranged at a finepitch.

The conductive particles 25 b are in contact with, and thus electricallyconnect, the source COF section connectors 21 a with the correspondingconnectors 15 b.

Accordingly, in this mounting structure, a driving signal which isoutput from each source COF section 21 is input to the liquid crystaldisplay panel 11 (FIG. 1) via the source COF section connector 21 a, theconductive particles 25 b, the connector 15 b, and the source connector15.

Each recessed portion 15 a is formed to have a trapezoidal cross-sectionsuch that the area of the top plane is larger than the area of thebottom surface. The area of the top plane of the recessed portion 15 ais, for example, about 50 μm×1 mm, and the depth of the recessed portion15 a is several micrometers or less.

The source connector 15 includes a metal layer formed of Ta, Mo, Al orthe like, an ITO layer provided on the metal layer, and an insulatinglayer formed of TaO, SiN or the like (not shown). The insulating layeris provided to cover the ITO layer except for areas facing the sourceCOF section connectors 21 a. The insulating layer has a thickness ofseveral micrometers.

The source anisotropic conductive layer 25 is formed as follows.

A synthetic resin 25 a acting as an adhesive is prepared. The syntheticresin 25 a is a non-cured state, and contains, for example, anepoxy-based or acrylic resin.

In the synthetic resin 25 a, about 1,000 to 10,000 conductive particles25 b are dispersed per unit area (e.g., 1 mm²). The synthetic resin 25 acontaining the conductive particles 25 b is formed into a film having athickness of about 10 to 50 μm, a width of about 1 to 10 mm, and alength of about 10 to 400 m. The film is wound like a reel. A length ofthe film which is necessary for the source-side edge portion is cut out,and is located on the source-side edge portion. The film is heated, andthus the synthetic resin 25 a is cured. In this manner, the sourceanisotropic conductive layer 25 is formed.

Each of the conductive particles 25 b is formed as follows.

A plurality of insulating particles 25 c containing, for example, apolystyrene-based or phenol-based resin and having a particle diameterof 2 to 5 μm are mixed with an insulating synthetic resin containing,for example, an epoxy-based or acrylic resin such that the insulatingparticles 25 c are contained at a ratio of 20% by volume or greater. Theinsulating synthetic resin is in a non-cured state. The mixture isformed into a sphere having a diameter of about 10 to 20 μm. A surfaceof the sphere is plated with a conductive material containing gold,nickel or the like to a thickness of about 1 μm. Thus, the conductiveparticle 25 b is formed.

In the conductive particle 25 b thus formed, the spaces between theinsulating particles 25 c are filled with the insulating syntheticresins containing, for example, an epoxy-based or acrylic resin. Inother words, the conductive particle 25 b includes the plurality ofinsulating particles 25 c and a conductive cover plating which coversthe plurality of insulating particles.

When the conductive particle 25 b is compressed with a prescribedpressure in the state where the synthetic resin 25 a is not cured, theconductive plating cover of the conductive particle 25 b is broken. Whenthe conductive plating cover is broken, the plurality of insulatingparticles 25 c covered with the conductive plating cover are releasedand dispersed into the synthetic resin 25 a. The thickness of theconductive plating cover of the conductive particle 25 b is preferably0.1 μm or less such that the conductive plating cover is broken withcertainty when the conductive particle 25 b is compressed with aprescribed pressure.

The source anisotropic conductive layer 25, in the state where thesynthetic resin 25 a is not cured, is located on a prescribed area ofthe source-side edge portion so as to cover the source connector 15. Thesource COF sections 21 are provided at prescribed positions on thesource anisotropic conductive layer 25. The source COF section connector21 a of each source COF section 21 faces the corresponding recessedportion 15 a of the source connector 15.

The thickness of the source anisotropic conductive layer 25 ispreferably in the range of 10 μm to 50 μm inclusive, and especiallypreferably slightly less than 20 μm. The width of the source anisotropicconductive layer 25 is preferably in the range of 1 mm to 3 mminclusive.

The source COF sections 21 provided on the source anisotropic conductivelayer 25 are pressed at a pressure of 2 Mpa to 5 Mpa for 8 to 20 secondsusing a heated bonding tool (not shown).

The heating temperature of the bonding tool is set to be about 250° C.to 350° C. such that the final temperature of the source anisotropicconductive layer 25 is 160° C. to 220° C. The width of the bonding toolis preferably about the same as the width of the source anisotropicconductive layer 25, i.e., about 1 mm to 3 mm.

When the source COF sections 21 are pressurized by the bonding tool, thesource anisotropic conductive layer 25 is pressurized.

The source connector 15 and the source COF section 21 are assembled suchthat the gap between the surface of the source connector 15 and thesurface of the source COF section 21 is small. Therefore, in the casewhere the conductive particles 25 b are on the portions of the sourceanisotropic conductive layer 25, which are not in correspondence withthe recessed portions 15 a, those conductive particles 25 b are eachdesigned such that the conductive plating cover is broken by a forceapplied thereto, and the insulating particles 25 c covered with theconductive plating cover are dispersed in the synthetic resin 25 a.

The gap between the areas of an upper surface of the source connector15, which are not in correspondence with the recessed portions 15 a, anda lower surface of the source COF section 21 is filled with thesynthetic resin 25 a acting as an adhesive. Thus, the source COF section21 is mounted on the source connector 15, and adjacent source COFsection connectors 21 a of the source COF sections 21 are insulated fromeach other without being short circuited.

The source connector 15 and the COF section 21 are assembled such thatthe gap between the connectors 15 b on the bottom surfaces of therecessed portions 15 a and the lower surface of the source COF section21 are large, Therefore, the conductive particles 25 b flowing in therecessed portions 15 a are not provided with a large compressing forceand thus the conductive plating covers of the conductive particles 25 bare not broken, although the conductive particles 25 b are deformed.Thus, the conductive particles 25 b remain conductive and electricallyconnect the connectors 15 b and the source COF connectors 21 a.

As described above, the source COF section 21 is mounted on the sourceconnector 15, and the source COF section connectors 21 a areelectrically connected to the source connector 15 using the recessedportions 15 a formed in the source connector 15. The synthetic resin 25a of the source anisotropic conductive layer 25 bonds the source COFsection 21 and the portions of the source connector 15 which are not incorrespondence with the recessed portions 15 a. Since the gap betweenthe above portions and the COF section 21 is small, the thickness of thesource anisotropic conductive layer 25 can be reduced and thus theamount of the synthetic resin 25 a used for mounting the source COFsection 21 can be decreased.

The depth of the recessed portions 15 a is set to be, for example, 10 μmto 20 μm, such that the source COP section connectors 21 a and theconnectors 15 b are electrically connected to each other withoutbreaking the conductive plating covers of the conductive particles 25 bin the recessed portions 15 a.

The source anisotropic conductive layer 25 may contain insulatingparticles other than the insulating particles 25 a contained in theconductive particles 25 b. In more detail, the synthetic resin 25 a mayhave insulating particles, other than the insulating particles 25 ccontained in the conductive particles 25 b, dispersed therein. Theparticle diameter of such insulating particles is preferably in therange of 2 μm to 20 μm inclusive.

In the above example, the conductive particles 25 b each have aconductive plating cover and the conductive plating cover is broken by aforce applied to each conductive particle 25 b. The present invention isnot limited to such a form. According to the present invention, theconductive particles may be formed of a conductive material and theconductive particles may be divided into a plurality of conductiveparticle portions by a force applied to the conductive particles.

FIG. 3 is a cross-sectional view of a mounting structure of a source COFsection of a liquid crystal display apparatus according to anotherexample of the present invention. The cross-sectional view shown in FIG.3 corresponds to that of FIG. 2. Namely, FIG. 3 shows a mountingstructure of the source-side edge portion.

The mounting structure shown in FIG. 3 is identical with that shown inFIG. 2, except that conductive particles 25 d are formed of a conductivematerial and insulating particles 25 e were not contained in, andreleased from, the conductive particles 25 d. The conductive particles25 d are designed to be divided into a plurality of conductive particleportions when being supplied with a prescribed level of force.

One conductive particle 25 d is compressed to be divided into aplurality of conductive particle portions 25 f. The conductive particleportions 25 f are not in contact with each other. Thus, adjacent sourceCOF section connectors 21 a are not short circuited.

The gate anisotropic conductive layer 26 has substantially the samestructure as that of the source anisotropic conductive layer 25. Thegate connector connected to the gate COF section 22 has substantiallythe same structure as that of the source connector 15. The gate COPsection 22 is mounted on the gate connector. The common panel connectorconnected to the signal input FPC section 23 has substantially the samestructure as that of the source connector 15.

As described above, according to the present invention, a force isapplied to conductive particles and the conductive particles is changed(in the example shown in FIG. 2, the conductive plating covers arebroken; and in the example shown in FIG. 3, the conductive particles aredivided into a plurality of conductive particle portions). As a result,the conductive property of the anisotropic conductive layer provided bythe conductive particles is changed to an insulating property. In thismanner, the conductive property of a prescribed portion of ananisotropic conductive layer can be changed to an insulating property bya force applied to the conductive particles.

In principle, a force may be applied to one of a plurality of conductiveparticles to change the conductive particle. Thus, the conductivity ofthe portion of the anisotropic conductive layer provided by theconductive particle can be changed to be an insulating property.

In this specification, the “change of a conductive particle” does notmean the deformation of the conductive particle, but the “change of aconductive particle” contributes to a change of the conductivity of theanisotropic conductive layer.

In the above description, the conductive “particles” are used forillustration. The conductive material body according to the presentinvention is not limited to particles. The present invention isapplicable to any shape or form of conductive material body.

In the above description, the source anisotropic conductive layer 25 isa film-type anisotropic conductive layer (ACF: Anisotropic ConductiveFilm). The anisotropic conductive material body according to the presentinvention is not limited to a film. The present invention is alsoapplicable to, for example, ACP (Anisotropic Conductive Paste). Inconsideration of the ease of handling, ACF is preferable.

In the above description, the conductive members are dispersed in asynthetic resin. The present invention is not limited to this, and theconductive members may be dispersed into any insulating medium.

In the above description, a COF system liquid crystal display apparatusis used in which a COF section is provided on a liquid crystal displaypanel. The present invention is not limited to this. The presentinvention is also applicable to a structure in which a recessed portionis to be electrically connected a conductive particle and the rest isconvexed. For example, the present invention is applicable to astructure disclosed by Japanese Laid-Open Publication No. 10-161093, inwhich a substrate (glass or plastic) has a groove and a connectorprovided at the bottom of the groove. The other areas of the surface ofthe substrate do not need to be flat. The present invention isapplicable to a structure in which a multi-layer flexible substrate hasa groove and a connector provided at the bottom of the groove. Insteadof the COF sections, TCP, COG, PPC and the like are also usable.

According to the present invention, the conductive property of aprescribed portion of an anisotropic conductive material body can bechanged to an insulating property by applying a force to the conductivemember via a medium. When the conductive member is supplied with noforce or is not supplied with a sufficient force to change theconductive member, the prescribed portion of the anisotropic conductivematerial body can be kept conductive.

In a display apparatus according to the present invention, the panelconnector and the driving circuit connector can be electricallyconnected with each other. Adjacent driving circuit connectors arrangedat a fine pitch can be insulated from each other. Thus, the reliabilityof the mounting structure for mounting the driving circuit on thedisplay panel can be significantly improved.

A method for producing a display apparatus according to the presentinvention allows a highly reliable mounting structure to be producedeasily.

The present invention provides a conductive member suitable to theanisotropic conductive material body.

Various other modifications will be apparent to and can be readily madeby those skilled in the art without departing from the scope and spiritof this invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the description as set forthherein, but rather that the claims be broadly construed.

1. An anisotropic conductive material body, comprising: an insulatingmedium; and a plurality of conductive members dispersed in the medium;wherein: at least a surface of each of the plurality of conductivemembers is conductive; and a force is applied to at least one of theplurality of conductive members so as to change the at least oneconductive member, so that the conductive property of the anisotropicconductive material body provided by the at least one conductive memberis changed to an insulating property.
 2. An anisotropic conductivematerial body according to claim 1, wherein the medium is adhesive. 3.An anisotropic conductive material body according to claim 1, whereinthe medium is formed of a synthetic resin.
 4. An anisotropic conductivematerial body according to claim 1, wherein the plurality of conductivemembers are a plurality of conductive particles.
 5. An anisotropicconductive material body according to claim 1, wherein: the plurality ofconductive members each include a plurality of insulating particles anda conductive plating cover for covering the plurality of insulatingparticles; and the change in the at least one conductive member includesbreakage of the conductive plating cover of the at least one conductivemember.
 6. An anisotropic conductive material body according to claim 5,wherein: the plurality of conductive members are a plurality ofconductive particles; and the plurality of conductive particles eachhave a particle diameter of 10 to 20 μm inclusive, and the plurality ofinsulating particles each have a particle diameter of 2 to 5 μminclusive.
 7. An anisotropic conductive material body according to claim1, wherein the change in the at least one conductive member includesdivision of the at least one conductive member.
 8. An anisotropicconductive material body according to claim 1, further comprising aplurality of insulating particles dispersed in the medium.
 9. Ananisotropic conductive material body according to claim 8, wherein theplurality of insulating particles each have a particle diameter of 2 to20 μm inclusive.
 10. An anisotropic conductive material body accordingto claim 1, wherein the medium is film-like.
 11. A display apparatus,comprising: a display panel; a driving circuit for driving the displaypanel; a driving circuit connector provided on the driving circuit; apanel connector provided on the display panel; and an anisotropicconductive material body for electrically connecting the driving circuitconnector and the panel connector to each other; wherein: theanisotropic conductive material body includes an insulating medium, anda plurality of conductive members dispersed in the medium; at least asurface of each of the plurality of conductive members is conductive;and a force is applied to at least one of the plurality of conductivemembers so as to change the at least one conductive member, so that theconductive property of the anisotropic conductive material body providedby the at least one conductive member is changed to an insulatingproperty.
 12. A display apparatus according to claim 11, wherein theanisotropic conductive material body is used for mounting the drivingcircuit on the display panel.
 13. A display apparatus according to claim11, wherein a gap between the driving circuit connector and the panelconnector is larger than a gap between a portion of the driving circuit,which is not in correspondence with the driving circuit connector, andthe panel connector.
 14. A display apparatus according to claim 11,wherein: the anisotropic conductive material body is provided betweenthe driving circuit and the display panel and between the drivingcircuit connector and the panel connector; and a gap between the drivingcircuit connector and the panel connector is designed such that theconductive property provided by the conductive member existing in thegap is not changed to an insulating property; and a gap between theportion of the driving circuit, which is not in correspondence with thedriving circuit connector, and the panel connector is designed such thatthe conductive property provided by the conductive member existing inthe gap is changed to an insulating property.
 15. A display apparatusaccording to claim 11, wherein the panel connector has a recessedportion facing the driving circuit connector.
 16. A display apparatusaccording to claim 11, wherein: the plurality of conductive members eachincludes a plurality of insulating particles and a conductive platingcover for covering the plurality of insulating particles; and the changein the at least one conductive member includes breakage of theconductive plating cover of the at least one conductive member.
 17. Adisplay apparatus according to claim 11, wherein the change in the atleast one conductive member includes division of the at least oneconductive member.
 18. A conductive member, wherein at least a surfaceof the conductive member is conductive, and the conductive member ischanged by a force applied thereto, such that the conductive property ofan anisotropic conductive material body forming the conductive member ischanged to an insulating property.
 19. A conductive member according toclaim 18, which is divided by a force applied thereto.
 20. A conductivemember, comprising: a plurality of insulating particles; and aconductive plating cover for covering the plurality of insulatingparticles; wherein at least a surface of the conductive member isconductive, and the conductive member is changed by a force appliedthereto, and the conductive plating cover is broken when a force isapplied to the conductive member.
 21. A conductive member according toclaim 20, which is a conductive particle, wherein the conductiveparticle has a diameter of 10 to 20 μm inclusive, and the plurality ofinsulating particles each have a particle diameter of 2 to 5 μm.